Laboratory: Oak Ridge National Laboratory
Title: Nanostructured Surface Preparation using Laser Interference Structuring
Class: Characterization
Computational
Processing/Manufacturing
 Mechanical Behavior
 Fabrication & Synthesis
of Materials
 Joining
Description: The laser-assisted interference technique involves two or more beams to create power
variation on a surface. Those beams are guided to the sample surface by overlapping each
other with defined angles to one another. Instead of simply adding intensity, the coherent
beams create an interference pattern. This allows a microscopic modulation and creates a light
pattern without any loss of energy during the interference process. Patterns can be dot, line,
and ring shaped.
Capability ORNL’s advanced laser structuring facility includes a Q-switched Nd:YAG (neodymium-doped
Bounds: yttrium aluminium garnet) laser system with a harmonic generator that allows for the
selection of one of four very sharp wavelengths: 1064, 532, 355, or 266 nm. The trigger
system’s frequency 10Hz, and the pulse duration is 10 ns, which accommodates heating and
cooling rates above 1012K/s.
Unique Aspects: Laser-assisted surface structuring has been proven for lubrication, adhesive bonding of
dissimilar materials (Al, carbon fiber polymer composites, Mg, steel), and wear resistance
applications. The following structure capabilities are possible (surface morphology is shown in
Figure 1):





Ondulation spacing : 0.5–
Density: 200–20,000/cm
Feature size: 1–500 nm
Structured area: 0.27 cm2/shot
Velocity: 10,000 lines at a time and 79 million dots at a time, up to 162 cm2/min.
In addition, several high-power and long-pulse systems are available.
Availability: These facilities are available for various partnership arrangements with industry.
Capability Dr. Adrian Sabau, Senior Staff Scientist, [email protected], 865-241-5145
Expert:
Image(s):
157 LightMAT Capability
July 2016
Alternating, high-power and low-power
profile created by wave interference
yields localized melting, solidification, and
surface structuring.
All results were obtained without empirical, labor-intensive
surface preparation methods that are incompatible with
Results for
joining of Al
carbon fiber polymer
composites (CFPC)
automation
required
byto automotive
manufacturing
Laser spot.
2 pulses/spot
22 µm
20 µm
Bonded as-received
Flat adhesive-resin interface
Bonded after laser structuring: Undamaged CF
References:
Laser-interference technique is
effective at removing surface
contaminants while structuring both
the AL and CFPC surfaces.
Clean fracture surfaces after
shear lap testing indicate poor
adhesive adherence with current
surface preparation.
Failure in the composite of laserstructured surfaces after shear-lap
testing indicate enhanced bonding
of adhesive to both Al and CFPC.
2 laser shots per spot
Plans for Industry Adoption: A follow-on effort is needed to demonstrate in a production
environment this multi-materials joining capability for wide-acceptance by the automotive industry.
A.S.The
Sabau,
J. Chen, J. F. Jones,
A. Hackett,
G. needs
D. Jellison,
Daniel, for
D. Warren,
J. D. industrial
Rehkopf,
laser-interference
structuring
technique
to be C.
scaled-up
large volume,
scaleModification
production in of
collaboration
withPolymer
Tier1 Suppliers
and leading
suppliers
of robotically
Surface
Carbon Fiber
Composites
after Laser
Structuring,
2015 TMS
controlled
lasers
to the automotive
industry:Adv. Composites for Aerospace, Marine, and Land
Annual
Meeting
& Exhibition,
Proceedings:
(1) Need the proof-of-concept for joining CFPC with Mg, Advanced High Strength Steel (AHSS),
Applications
II, Orlando,
Florida.
and Al using
a typical wavelengths
used in industry (i.e., 1 micron optical-fiber friendly);
(2) An optical head capable of handling laser processing in an automated environment needs to
Managed by UT-Battelle
be
developed;
for the
Department
of Energy J. F. Jones, A. Hackett, G. D. Jellison, C. Daniel, and D. Warren, "Aluminum
J. Chen,
A.S. Sabau,
Surface Texturing by Means of Laser Interference Metallurgy," 2015 TMS Annual Meeting &
Exhibition, Proceedings: Light Metals 2015: Aluminum Processing, pp. 427-429, Orlando, Florida.
Website: http://web.ornl.gov/sci/physical_sciences_directorate/mst/pjg/adrian/web_smu_bio/index.html
157 LightMAT Capability
July 2016